Screening of Tropical Medicinal Plants for Molluscicidal,Larvicidal, Fungicidal and Cytotoxic Activities and Brine Shrimp Toxicity

Abstract

Crude Extracts Of 36 Medicinal Plants Collected In Africa and South America Were Tested For Their Molluscicidal (Biomphalaria Glabrata), Larvicidal (Aedes Aegypti), Fungicidal (Cladosporium Cu-Cumerinum) and Cytotoxic (Against 2 Human Colon Carcinoma Cell Lines) Activities, As Well As For Brine Shrimp Toxicity (Artemia Salina). Members Of The Annonaceae, Guttiferae and Leguminosae Are Shown To Contain Compounds Highly Active In These 5 Bioassays. Three Of The Species Tested Stand Out For Their Marked Activity In Only One Bioassay: Rogeria Adenophylla and Sesamum Indicum (Pe-Daliaceae) Demonstrate Potent Larvicidal Activity and Adenium Obesum (Apocynaceae) Exhibits Very Strong Cytotoxicity.     

Discriminant analysis and structure-activity relationships. 1. Naphthoquinones

Discriminant analysis has been used to study the data for naphthoquinones as antitumor agents in three different animal tumor systems. In each case the most significant variables for classifying the compounds into two groups according to their antitumor activities were determined by a stepwise procedure. The usefulness of discriminant analysis in the design of drugs is discussed.     

Naphthoquinones from Catalpa ovata and their inhibitory effects on the production of nitric oxide

Bioassay-guided fractionation of a CH2Cl2-soluble fraction of the stems of Catalpa ovata led to isolation of a new naphthoquinone, 4-hydroxy-2-(2-methoxy-3-hydroxy-3-methyl-but-1-enyl)-4-hydro-1H-naphthalen-1-one (10), together with nine known compounds, catalponol (1), catalponone (2), catalpalactone (3), α-lapachone (4), 9-hydroxy-α-lapachone (5), 4,9-dihydroxy-α-lapachone (6), 9-methoxy-α-lapachone (7), 4-oxo-α-lapachone (8), and 9-methoxy-4-oxo-α-lapachone (9). The structures were elucidated on the basis of spectroscopic analyses. The inhibitory effects of these isolates on lipopolysaccharide-induced NO synthesis in RAW 264.7 cells were evaluated. Among them, catapalactone (3), 9-hydroxy-α-lapachone (5) and 4,9-dihydroxy-α-lapachone (6) exhibited potent inhibitory effects, with IC₅₀ values of 9.80, 4.64 and 2.73 μM, respectively.     

Chemical constituents of the leaves of Diospyros kaki and their cytotoxic effects

Isolation and structure elucidation of two new compounds, kakispyrone (1) and kakisaponin A (2), together with 11 known compounds, from the leaves of Diospyros kaki L. are described. Their cytotoxic effects against several cancer cell lines (A549, HepG2 and HT29) are also reported.     

Antiviral Activities of Selected Medicinal Plants II: Effect of Extracts of Diospyros barteri,Diospyros monbutensis and Sphenocentrum jollyanum on Cowpea Mosaic Viruses

The hexane and methanol extracts of various morphological parts of Diospyros barteri Hiern, Diospyros monbutensis Gurke and Sphenocentrum jollyanum Pierre were screened for their effectiveness in the control of four mosaic viruses affecting cowpea (CMeV, CYMV, BICMV, and CABMVa). The methanol leaf extract of D. barteri at 1mgml –i concentration level was found to be more effective in the control of Cowpea Aphid-Borne Mosaic Virus (CABMVa - Onne strain) than all the other viruses investigated. Further investigation to prove the effectiveness of the D. barteri methanol leaf extract was carried out serologically by using the ELISA technique. The ELISA results confirmed the effectiveness of the D. barteri methanol leaf extract in the control of CABMVa (Onne strain) at 1mgml –i concentration level.     

Chemical constituents of the leaves of Diospyros kaki and their cytotoxic effects

Isolation and structure elucidation of two new compounds, kakispyrone (1) and kakisaponin A (2), together with 11 known compounds, from the leaves of Diospyros kaki L. are described. Their cytotoxic effects against several cancer cell lines (A549, HepG2 and HT29) are also reported.     

Synthesis of α‐ and β‐Pyran Naphthoquinones as a New Class of Antitubercular Agents

A series of α‐ and β‐pyran naphthoquinones (lapachones) have been synthesized and evaluated for their in‐vitro antibacterial activity against Mycobacterium tuberculosis strain H37Rv (ATCC 27294) using the Alamar‐Blue susceptibility test; the activity was expressed as the minimum inhibitory concentration (MIC) in μg/mL. The synthetic methodology consisted of the formation of methylene and aryl o‐quinone methides (o‐QMs) generated by Knoevenagel condensation of 2‐hydroxy‐1,4‐naphthoquinone with formaldehyde and arylaldehydes. These o‐QMs then undergo facile hetero Diels–Alder reactions with dienophiles in aqueous ethanol media. Some naphthoquinones exhibited inhibition with MIC values of 1.25 μg/mL, similar to that of pharmaceutical concentrations currently used in tuberculosis treatment. These results justify further research into the value of these quinones as part of an original treatment for tuberculosis.     

Molluscicidal and trypanocidal activities of lapachol derivatives

The activity of the potassium salt of lapachol against the snail Biomphalaria glabrata and its egg masses was tested. The obtained IC50 values (2.70 ppm and 1.43 ppm, respectively) are indicative of a strong activity. Lapachol derivatives were also assayed against infective trypomastigote blood forms of T. cruzi and the triacetoxy derivative of reduced lapachol showed relevant trypanocidal activity, killing 95.7% of the parasites at the concentration of 42 microg/mL.     

Molluscicidal and antischistosomal activities of Zingiber officinale

Experiments were conducted to study the major constituents of Zingiber officinale responsible for its molluscicidal activity and the effect of the active component on different stages of Schistosoma mansoni. Gingerol and shogaol exhibited potent molluscicidal activity on Biomphalaria glabrata. Gingerol (5.0 ppm) completely abolished the infectivity of Schistosoma mansoni miracidia and cercariae in B. glabrata and mice, respectively, indicating that the molluscicide is capable of interrupting schistosome transmission at a concentration lower than its molluscicidal concentrations.     

The isolation of Nb-methyl-antirhine, malindine and isomalindine from Strychnos usambarensis

Three quaternary alkaloids have been isolated from root barks of STRYCHNOS USAMBARENSIS Gilg from Rwanda: malindine, isomalindine and Nb-methyl-antirhine. The structure elucidation and the stereochemistry of the new isomalindine has been proposed based on its spectral data and their comparison with those of malindine, its isomer.     

Antiamoebic and antiplasmodial activities of alkaloids isolated from Strychnos usambarensis.

Seven alkaloids isolated from Strychnos usambarensis have been assessed for in vitro activities against Entamoeba histolytica and Plasmodium falciparum and for in vivo activity against Plasmodium berghei in mice. Strychnopentamine and 3',4'-dihydrousambarensine were highly active against P. falciparum in vitro, but were inactive and non-toxic against P. berghei in vivo. Usambarensine, usambarine, and 18,19-dihydrousambarine were highly active against E. histolytica in vitro, but were less active against P. falciparum in vitro. Nb-Methylusambarensine was less active against both protozoa than was usambarensine, and akagerine possessed little antiprotozoal activity. Structure-activity relationships are discussed in the context of the reported cytotoxic and pharmacological properties of these alkaloids.     

Molluscicidal Properties of Agave Americana and Balanites Aegyptica

Abstract

Agave Americana and Balanites Aegyptica Were Evaluated For Molluscicidal Properties Against Eggs and Adults Of Three Species Of Freshwater Snails, Lndoplanorbis Exustus, Lymnaea Luteola and Gyrau-Lus Convexiusculus and For Haemolytic Activity With Sheep Red Blood Cells. Further Studies Were Then Performed With Extracts Of The Leaves Of A. Americana and The Fruits Of B. Aegyptica, and A. Americana Was Found To Be More Effective Against All Stages Of Snail Development.     

芳酰基氟尿嘧啶衍生物的合成及其抗肿瘤活性

采用２－取代－５－氟－３Ｈ－４－嘧啶酮与芳酰氯在丙酮中于三乙胺存在下反应,合成了１７个２－取代－３－芳酰基－５－氟－４－嘧啶酮类化合物。目标化合和的的结构经ＩＲ、＾１Ｈ－ＮＭＲ、元素分析或ＭＳ确定,初步生物活性测定显示,部分化合物具有一定的抗肿瘤活性。     

Screening of European Fungi for Antibacterial,Antifungal, Larvicidal,Molluscicidal, Antioxidant and Free-Radical Scavenging Activities and Subsequent Isolation of Bioactive Compounds

Crude extracts of 57 species of European fungi have been tested for their bactericidal (Bacillus subtilis, Escherichia coli), fungicidal (Candida albicans, Cladosporium cucumerinum), larvicidal (Aedes aegypti), molluscicidal (Biomphalaria glabrata), antioxidant and free-radical scavenging activities. Connatine and 2(3,4-dihydroxyphenyl)glycine, two compounds with antioxidant and free-radical scavenging properties, were subsequently isolated from the methanolic extracts of Lyophyllum connatum (Tricholomataceae) and Cortinarius hercynicus (Cortinariaceae), respectively. In addition, linoleic acid was shown to be molluscicidal.     

Fungicidal and toxicological properties of functionally substituted nitrobenzofuroxanes

The fungicidal activities of 5-nitro-4,6-dichlorobenzofuroxane, 4,6-dinitro-5,7-dichlorobenzofuroxane, and a mixture of these two compounds were studied. The main toxicological characteristics of biologically active functionally substituted nitrobenzofuroxanes were identified. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 42, No. 4, pp. 27–29, April, 2008.